High melting point wax



Patented Oct. 20, 1931 untrue er TATENT @FHCE teases;

CLIFFORD C. BUCHLER, OF CASPER, wxomme. ASSIGNOR TO STANDARD OIL COM-PAM, OF WRITING, INDIANA. A CORPORATION OF INDIANA.

HIGH MEETING WENT WAX No Drawing. Application filed March 5,

This invention relates to the production of high melting point waxesfrom petrolatum by filter pressing and sweating.

Heretofore it has not been possible to press a and sweat petrolatum. Thepresent invention is based upon the discovery that a. petrolatumdistillate containing a suitable amount of diluent may be readilypressed at appropriate temperatures to produce a filter cake which canbe satisfactorily sweated to a substantial yield of high melting pointwax.

The distillation of the petrolatum ordinarily should be conducted at atemperature which will cause slight decomposition but excessivedestruction of the high melting point wax should beprevented byconducting the distillation under conditions characteristic ofsub-atmospheric distillation, that is, under vacuum or with steam orunder vacuum with steam. A substantial percentage of the petrolatumshould be distilled over in order to ensure a good recovery of wax.Ordinarily the distillate is unpressable and requires to be diluted witha suitable amount of a petroleum distillate such as naphtha. to renderit Pressable. The addition of too much naph- F tha will render the waxunpressablc, but the range of addition of naphtha which will ensure apressable stock'is broad and no difficulty is experienced in determiningan amount of naphtha to be added which will ensure satisfactorypressing. The amount of oil in the filter cake must be carefullyregulated. If this oil-content is too high clifliculties are experiencedin pressing and sweating and the yield of sweated high melting point waxis seriously diminished. The oil-content of the filter cake iscontrolled by regulating the amount of diluent added and the temperatureof pressing. The oil-content of the wax cake diminishes with reductionof the amount of diluent and increases with the reduction of thepressing temperature. To sum up, the process involves the addi- 19%..Serial No. 259,873.

tion of a quantity of diluent to the wax distillate which will ensure apressable distillate and in conjunction with the conditions of presslng,will ensure a filter cake of such low oil content that it can be readilysweated.

It is obvious that the conditions necessary for various wax distillateswill vary considerably and that it is not possible to set forth specificfigures which would be applicable to all distillates. However, I believethat satisfactory results can be obtained from most petrolatums byfollowing the teaching of the appended specific example, with slightchanges which may be necessitated for pctrolatum distillates of somewhatdifferent character.

, Example Petrolatum wax derived from the first centrifuging of a diluteand chilled reduced crude oil, and having a melting point of about 150F. and an oil content of about 39%, is heated in a still to about 500 F.Steam is then supplied to the still and the temperature is rapidlyraised to a maximum of about 800 An overhead amounting to about 70% ofthe charge and having a melting point of about 122 F. and an oil-contentof about 52%, is obtained. This overhead cannot be readily pressed butif it is diluted to give a stock containing between about 10% and about65% of naptha it may be pressed without difliculty. I have found thatfor the wax distillate indicated the optimum content of naphtha is about15%. The distillate thus diluted is chilled to about 7 4 F. andfilter-pressed at a temperature of 7478 F. The pressing occupies eighthours and the maximum pressure is about 120 lbs. per square inch. Ayield of about 26% of wax cake is obtained, which contains about 8%naphtha and 8% of oil. I have found that the oil content should becontrolled by the amount of dilution and temperature of pressing so thatthe oilcontent should preferably not exceed'10%,

in order to ensure a satisfactory sweating yield. The filter-cake has amelting point, after removal of naphtha of about 148 F. The filter-cakeis subjected to sweating for 5 several days at a temperature rising from110 F. to about 150 F., giving about 59% of wax containing about 1.5% ofoil, having a melting point of 154 F. (155 A. S. T. M.) and of goodcolor. The yield is about 14% of the initial petrolatum. The dripscontain a substantial quantity of wax and may be readily resweated atslightly lower temperatures to give a substantial yield of wax ofsomewhat lower melting point.

By way of comparison it may be stated that on diluting similardistillate wax to a naphtha content of about 30% bv weight and pressingbetween 67 and 70 F., a wax-cake containing about 14% of oil isobtained, while if the pressing is effected at about 70 to 74 F., theoil content is about 11%. As illustrative of the eti'ect of oil uponsweating, it maybe stated that a composite wax thus obtained andcontaining about 12% of oil and having a melting point of 144 F., aftersweating over several days, with a temperature rising from 110 F. to 145F. gives a 48% yield of wax having a melting point of 150 fi F. and anoil content about 7%.

Although the present invention has been described in connection with thedetails of a specific example, it must be understood that such detailsare not intended to be limitive upon the scope of the invention exceptin so far as included in the accompanying claims. 1

I claim:

1. The method of producinghigh melting point wax from petrolatum waxwhich consists in distilling the petrolatum wax under conditionscharacteristic of sub atmospheric distillation, diluting thedistillatewith an oil miscible diluent and filter pressing the diluteddistillate under temperature conditions which give a sweatable cake, andsweating the filter cake. i

2. The method of producing high melting point wax from petrolatum waxwhich consists in distilling the petrolatum wax under conditionscharacteristic of sub-atmospheric distillation, diluting the waxdistillate with low boiling petroleum distillate to form a dilutedproduct containing between 10 and of the petroleum distillate from whichthe wax may be readily pressed at a suitable pressing temperature,pressing the diluted wax distillate at such temperature, and sweatingthe filtered wax.

; 3. In the treatment of petrolatum wax, the steps of distilling thepetrolatum wax under conditions characteristic of sub-atmosphericdistillationand diluting the wax distillate .9 petroleum distillate fromwhich pressable wax may be separated by pressing the diluted distillateat suitable pressing temperatures.

4. The method of producing high melting point wax from petrolatum waxwhich consists in distilling the petrolatum wax under conditionscharacteristic of sub-atmospheric distillation, diluting the distillatewith petroleum distillate, and filter pressing the diluted distillateunder temperature conditions which give a sweatable cake of relativelylow oil content, and sweating the filter cake.

5. The method of producing high melting point wax from petrolatum waxwhich consists in distilling the petrolatum wax under conditionscharacteristic of sub-atmospheric distillation, diluting the waxdistillate with low boiling petroleum diluent to form a prodnotcontaining between 10 and 65% of petroleum diluent whereby suchdistillate is filter pressable at a suitable pressing temperature,pressing the diluted wax distillate at such temperature, and sweatingthe filtered wax.

6. In the treatment of petrolatum wax, the steps of distilling thepetrolatum wax under conditions characteristic of sub-atmosphericdistillation and diluting the wax distillate with a petroleum distillateto form a product containing between 10 and 65% of petroleum distillatewhich is filter pressable at suitable pressing temperatures to give acake of relatively low oil content.

7. The method of producing high melting point wax which consists indistilling petrolatum wax under conditions characteristic ofsub-atmospheric distillation to obtain about distillate, diluting thedistillate to a naphtha content of about 15%, chilling the diluteddistillate to about 74 F. and filtering at about 74 to 78 F., andsweating the separated wax.

8. The method of producing high meltlng point wax which consists indistilling petrolatum wax under conditions characteristic ofsub-atmospheric distillation, diluting the wax distillate with petroleumdistillate to form a product containing between 10 and 65% of petroleumdistillate whereby on cooling the distillate may be pressed to g1ve acake containing less than about 10% of oil, pressing the diluteddistillate to producea cake containing less than about 10% of 011, andsweating the separated wax.

9. In the treatment of petrolatum wax, the steps of distilling thepetrolatum wax under conditions characteristic of sub-atmosphericdistillation, diluting the wax distillate with an oil miscible diluentto form a product containing between 10 and 65% of the diluent, andcooling the diluted distillate to a. temperature at which the wax may beseparated therefrom.

10. In the treatment of petrolatum wax, the steps of distilling thepetrolatum wax under conditions characteristic of sub-atmosphericdistillation, diluting the wax distillate with an oil miscible diluentto form a; roduct containing between 10 and 65% of t e diluent, coolingthe diluted distillate to a temperature at which. the wax may beseparated 5 therefrom, separating the wax therefrom,

and sweating the separated wax.

In testimony whereof, I have hereunto set my hand and seal this 1st dayof March,

CLIFFORD C. BUCHLER.

